This invention relates, in general, to an apparatus for singulating individual parts, and more particularly to an apparatus having a shutter assembly capable of singulating packaged integrated circuit parts.
In the semiconductor industry, packaged integrated circuits must pass a series of electrical tests, as well as visual inspections, in order to be released to the customer. Inherent in many test and inspection regimes is the separation of single units from a plurality of units, a step commonly referred to as singulation. Further, upon completion of the testing and inspection phases, units that have failed either phase must remain separated from those that pass. Those units that have failed are referred to as reject material and typically are discarded.
Semiconductor device manufacturers have employed several different types of equipment to accomplish the task of singulating units. Some of the more common means for singulating include a motor driven two wheel system, solenoid driven machinery, systems using reciprocating parts, and systems using gates and shutters. The two most important drawbacks for these types of systems are the increased cycle times introduced by these types of apparatus and the cost for maintaining these systems. In addition, machines requiring air cylinders or solenoids for singulating parts use up time without moving the parts. Sorting mechanisms using reciprocating parts that must move and return waste time on the return. Gates and shutters are slow because they must be activated by solenoids or other means.
A high-speed integrated circuit handler was disclosed by Frisbie et. al. in U.S. Pat. No. 4,128,174 which addressed the issue of cycle time when testing and sorting integrated circuit parts. This U.S. patent is hereby incorporated herein by reference. In this patent a means for separating individual parts, having a sort wheel and a test wheel, was presented. This apparatus offered several advantages including the use of an electronic, rather than a mechanical, means for controlling the speed and positioning of both the sort and test wheels. Further, neither wheel has to return to a start position after completing an operation. Unfortunately, some drawbacks occur because of space limitations such that the sort wheel was rendered infeasible. Further, alignment between the sort and test wheels must be correct, and although the apparatus decreased cycle time significantly the alignment of sort wheel to test wheel does require time.
Accordingly, it would be beneficial to have an apparatus for separating and sorting individual parts in a fast and accurate manner while simultaneously minimizing the area required by the apparatus. Moreover, it would be beneficial to have an improved apparatus with less complex means for accomplishing the functions of separating and sorting. Finally, it would be advantageous for the system to be inexpensive to purchase as well as to maintain.